BartSr: that, sir, is pretty doggone ingenious, and makes perfect sense! Thanks for the tip.
Could you use the acid sharpening method like is used on some files?
Even with all the previous posts about sharpening or re-purposing old files and rasps, it had never even occurred to me until seeing this question:
many (not "all", but many) horseshoeing/farrier/blacksmith supply stores offer rasp and file sharpening services. Some are better than others, and of some of those "better" sharpening services, some are downright outstanding. In my experience, most seemed to use an acid-bath process.
Back when I was a perfeshunal horse-crippler, I'd only buy premium quality hoof rasps, files, etc... then promptly send the brand-new, unused rasps off to be sharpened, and the difference between a brand-new rasp, as shipped, and a brand-new rasp, sharpened, was extremely obvious. As it was explained to me, many (if not all) file and rasp manufacturers are a bit hesitant to put an extreme edge on their tools, due to possible liability. (Anyone who's ever accidently run a brand new rasp over their offhand thumb knuckle, or let one slip through their gripping hand, can easily imagine where some of today's over-sensitive, litigiously-inclined folks might find a sharp tool to be an easy way to an early retirement.)
Anywho: a good local shoeing supply store just might be another answer to the boxes of old dull files we all seem to collect.
